https://jornada.nmsu.edu/ltar
https://lter.jornada.nmsu.edu/data-catalog/
Other data can be found here.
* Abstract: reference harvest measurements for the long-term Net Primary Production (NPP) study at the Jornada Basin LTER. Data here include horizontal cover, vertical height, and aboveground biomass of plants harvested near, but outside, a grid of permanent NPP quadrats at each of 15 NPP sites. These sites were selected to represent the 5 major ecosystem types in the Chihuahuan Desert (upland grasslands, playa grasslands, mesquite-dominated shrublands, creosotebush-dominated shrublands, tarbush-dominated shrublands). For each ecosystem type, three sites were selected to represent the range in variability in production and plant diversity; thus the locations are not replicates. At each site, a 1 hectare area was fenced in 1988 and a grid of 49 (48 at one playa location) 1m x 1m replicate quadrats was laid out when sampling began in 1989. Harvests are made outside the quadrat grid, but inside the fence. Height and cover are recorded in the field. Live biomass is weighed in the lab and all measurements are recorded as reference harvest data. Subsequently, regressions between the harvested biomass and plant volume values are used to derive allometric equations that determine biomass from non-destructive volume measurements in the permanent NPP quadrats. Further details are described in the methods metadata. This is an ongoing study with new harvest data (from selected species) collected in the spring, fall, and winter each year. Attention: These data are not appropriate for estimates of percentage cover because of the way the data are collected.
* “Subsequently, regressions between the harvested biomass and plant volume values are used to derive allometric equations that determine biomass from non-destructive volume measurements in the permanent NPP quadrats.” - We are looking at reporting ANPP (annual net primary productivity) values for the respective sites. Can we use the values reported in this document or do we need the alometric equations to calculate the NPP?
* data from: 5 major ecosystem types in the Chihuahuan Desert (upland grasslands, playa grasslands, mesquite-dominated shrublands, creosotebush-dominated shrublands, tarbush-dominated shrublands)
* Measure: Collected from permanent grids within an exclosure.
* Method:
* Bounding Box of:
-106.865
-106.713
32.669
32.488
Can I get lat/long for the 15 NPP sites?
ANPP is currently being calculated as the sum across functional types by site-year-season, then selection of the max NPP value within that year. Do we need to change this selection process?
Chris Dorich (chris.dorich@colostate.edu)
Colorado State University
November 13, 2020